Broadcast segments include live programs, taped programs, streaming programs, commercials and the like. These segments may be aired according to a wide variety of schedules, for example, national coverage, particular geographic coverage or to fill otherwise unreserved programming slots. Furthermore, the scheduled broadcast time may be uniform nationwide or vary according to a broadcaster's local considerations.
Conventional systems exist where segments may be independently detected to determine when segments, such as performances, scenes, commercials, or the like were actually broadcast over a given channel or by a given station.
One such system involves the use of passive recording methods that are characterized by the presence of a device that attempts to sense, in real time, the broadcast segments to which an audience member is exposed and record this information, which would later be retrieved at or uploaded to a centralized data processing facility. Since the information would be collected in computer readable form, data processing could be carried out readily with the use of a passive recording apparatus. Information collected by passive recording would be free of human error, and in this respect would enjoy improved reliability.
Devices known as “personal passive people meters”, which are small and portable, have been proposed. Such devices are intended to be carried by persons whose broadcast segment exposure would be monitored. These meters would permit viewer/listener determination at the individual level, which is highly desirable. Such meters may be optimized to correctly sense the segment to which a viewer is being exposed. Under certain proposed approaches, the meter may attempt to identify both unmodified broadcast segments, and segments modified before broadcast to make them more readily identifiable.
One approach to identification of unmodified segments involves pattern recognition. Each segment is analyzed before or after broadcast and its analyzed characteristics determine its “broadcast signature”. A table of broadcast signatures is created by, or made available to, each monitoring station. In operation, a monitoring station attempts to analyze the characteristics of a segment being broadcast and match it to one of the broadcast signatures, that is, recognize its pattern.
Several other identification approaches involve modifying the broadcast segments to provide a code which the detecting equipment is designed to recognize. An advantage of these approaches is that the monitoring stations need not be updated as new broadcast segments are created. Other approaches (such as the one proposed in U.S. Pat. No. 3,004,104) propose to suppress a narrow band of frequencies (10 Hz wide) in a portion of the voiceband (1000 Hz) at timed intervals according to a predetermined code. Still other approaches seek to modulate the audio frequency subcarrier with an identifying code of narrow bandwidth (100 Hz) and short duration (3 seconds) at the start and end of each segment. Still other approaches propose to mix subaudible-frequency identifying codes with conventional audio in the program segments. A technique proposed for use with a musical recording comprises eliminating a sequence of six frequency bands from an audio signal, with the sequence varying during the course of the signal, and in place of the eliminated frequencies, inserting a sequence of code signals.
A more advantageous approach to identifying broadcast segments is disclosed in U.S. Pat. No. 7,316,025, titled “Method and Apparatus for Encoding/Decoding Broadcast or Recorded Segments and Monitoring Audience Exposure Thereto,” which is incorporated by reference in its entirety herein. Under this approach, information is encoded in broadcast or recorded audio signals. A code signal having a predetermined bandwidth is modulated with an identification signal having a narrower bandwidth than the predetermined bandwidth to produce an encoded signal. The encoded identification signal is mixed with the broadcast or recorded audio signal to produce an output signal.
The audio signal portion may be correlated with a copy of the code signal to recover the identification signal. The correlating may be carried out by a personal unit worn or carried on the person of an audience member, that produces a record of the broadcast or recorded segments to which the audience member has been exposed. This record, with identification of the audience member, is uploaded to a centralized facility. Systems and methods for further processing the information for obtaining useful audience measurement data is disclosed in U.S. Pat. No. 7,222,071, titled “Audio Data Receipt/Exposure Measurement With Code Monitoring and Signature Extraction,” and U.S. Pat. No. 7,239,981, titled “Systems and Methods For Gathering Audience Measurement Data”, both of which are incorporated by reference in their entirety herein.
While various systems and methods have been proposed for audience measurement, little to no technical proposals have been made to measure and/or quantify audience engagement. Specifically, there is a need to objectively determine and/or measure levels of audience engagement, e.g., how “enthused” an audience member is with the content.